JoAnn,
  Basically the difference is that the 274x has aperture definitions in the
header of the gerber file.  This would allow you to give the file to some
one else without supplying an aperture list with defintions.  And they
could read the files in, if they have a gerber reader supporting 274x.
  However I still supply the fabrication house with an aperture listing and
definition.  I have experienced a few times where there has been
differences between the my hardcopy plots and the vendors plots.  These
usually are with custom apertures, that are defined by macros in the header.


  If you would like to know more about the format of the gerber language.
You may obtain from Gerber Scientific a book that has all the technical
definitions of the format.

  I use Ecam my self and have since Richard Nedbahl started the original
company. I would not be without a third party gerber viewer to check the
files before releasing to fab.  

I hope this helps....
Neil D....

>Good morning.  I am a relatively new printed board designer who
unfortunately 
>is unable to get a straight answer out of anyone here.  We are currently
using 
>Cadstar For Windows 2.2.2 to design our boards.  After the layout has been 
>approved by everyone, we view the spool files before sending them on for 
>prototyping or release in Cam350 or ECAM (depending on who has the key).  We 
>currently import the spool files and convert them using RS-274.  We have the 
>option of using RS-274-X though.  Could some kind soul explain the
difference 
>to me?  No one here can - we are all just winging it.  When I ask, I'm told 
>"That's the way we've always done it."  I refuse to accept that as a valid 
>reason.  No one here *ever* uses the IPC standards even though we do have a 
>copy of some of them on hand.  (Scary, ain't it?)
>
>I'd really appreciate some straight answers from others in the industry.  My 
>boss keeps saying "But the boards work.".  Surely they must be  a better way 
>and a more intelligent answer to my questions.
>
>Thank you
>
>JoAnn L. Amerson
>Design Librarian
>Red Lion Controls, Inc.
>E-mail: [log in to unmask]
>Voice: (717) 767-6961 ext 6308
>
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  / Neil Diamond      /  \
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